Power-packet-switching circuits (and methods and systems) in which at least one port uses series-connected combinations of bidirectional switches to connect a link inductor (or transformer), with selectable polarity, to an outside line. Optionally, series-connected combinations of bidirectional switches are used for phase legs in some ports, while single bidirectional switches are used for the phase legs in other ports. This can be particularly advantageous where the converter interfaces between lines at significantly different operating voltages. By using B-TRANs as the series-combined elements of the combinations of switches, voltage-dividing circuitry is not needed to equalize the voltages seen by the individual devices in each combination.